00:01
So for this problem, number 100, we know that the basic price for the internet is $30 per month for 1 ,000 minutes.
00:12
And you'll pay additional $0 .08 for each additional minute over the 1 ,000 minutes.
00:22
So this customer's bill, the lowest bill is let me write here.
00:31
Lowest is 36 .4.
00:49
Okay, so from here, we use this number to minus $30.
01:00
We know that the user actually pays $6 .4 extra.
01:07
So we use this to minus, to divide 0 .08, okay? so we know how many minutes he used over the 1 ,000 minutes basic plan.
01:28
Okay, so here we get 8 minutes.
01:32
So for the lowest bill's month, he used 1 ,000 plus 80 equals to 180 minutes.
01:52
So how about the highest bill? the months he pays the highest bill how many times did he use? so let's see, the highest month he pays for $47 .2 for the internet...